It depends what you're looking to do with it
I agree parts salvage would be a terrible idea for these, esp. considering they're conformal-coated. Some people like to collect interesting-looking old stuff as art. Personally I like finding old circuitry from unusual sources that's old enough it's not just a single SoC, to trace out the circuitry and figure out how it works as a mental puzzle. Some people like finding unusual old chips (like the Analog Devices hybrid above) to de-cap and look at the silicon dies.
Not inflating any prices though, these are all listed at what I paid for them - did I overpay? Sure, you could make an argument for that.
I do see similar stuff go for more all the time though on eBay or on the cpu-world forums, just figured I'd try here first as it's more pleasant dealing directly with people than through a company. If the "many threads" refers to the 2(?) others, same principle with those, that stuff's half or less the price of what I see similar things listed for (I did actually, as an experiment, try listing some of those Bruker boards from the other thread on eBay to see how it would work, and somebody bought the ADC one). If no bites for a while, then oh well, I try it on eBay instead or drop the price, that's how it goes.